TY  - JOUR
A1  - Zaccheus, Mona V.
A1  - Bröker, Nina Kristin
A1  - Lundborg, Magnus
A1  - Uetrecht, Charlotte
A1  - Barbirz, Stefanie
A1  - Widmalm, Goran
T1  - Structural studies of the O-antigen polysaccharide from Escherichia coli TD2158 having O18 serogroup specificity and aspects of its interaction with the tailspike endoglycosidase of the infecting bacteriophage HK620
JF  - Carbohydrate research
N2  - We have analyzed the O-antigen polysaccharide of the previously uncharacterized Escherichia coli strain TD2158 which is a host of bacteriophage HK620. This bacteriophage recognizes and cleaves the polysaccharide with its tailspike protein (TSP). The polysaccharide preparation as well as oligosaccharides obtained from HK620TSP endoglycosidase digests were analyzed with NMR spectroscopy. Additionally, sugar analysis was performed on the O-antigen polysaccharide and MALDI-TOF MS was used in oligosaccharide analysis. The present study revealed a heterogeneous polysaccharide with a hexasaccharide repeating unit of the following structure:
 alpha-D-Glcp-(1 -> 6) vertical bar vertical bar 2)-alpha-L-Rhap-(1 -> 6)-alpha-D-Glcp-(1 -> 4)-alpha-D-Galp-(1 -> 3)-alpha-D-GlcpNAc- (1 ->vertical bar beta-D-Glcp/beta-D-GlcpNAc-(1 -> 3)
 A repeating unit with a D-GlcNAc substitution of D-Gal has been described earlier as characteristic for serogroup O18A1. Accordingly, we termed repeating units with D-Glc substitution at D-Gal as O18A2. NMR analyses of the polysaccharide confirmed that O18A1- and O18A2-type repeats were present in a 1:1 ratio. However, HK620TSP preferentially bound the D-GlcNAc- substituted O18A1-type repeating units in its high affinity binding pocket with a dissociation constant of 140 mu M and disfavored the O18A2-type having a beta-D-Glcp-(1 -> 3)-linked group. As a result, in hexasaccharide preparations, O18A1 and O18A2 repeats were present in a 9: 1 ratio stressing the clear preference of O18A1- type repeats to be cleaved by HK620TSP.
KW  - Escherichia coli
KW  - Tailspike
KW  - Endoglycosidase
KW  - Lipopolysaccharide
KW  - NMR
KW  - Mass spectrometry
Y1  - 2012
U6  - https://doi.org/10.1016/j.carres.2012.05.022
SN  - 0008-6215
VL  - 357
IS  - 8
SP  - 118
EP  - 125
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - THES
A1  - Barbirz, Stefanie
T1  - Konservierte Struktur bei genetischer Mosaizität : die Tailspike Proteine dreier Phagen der Familie Podviridae
T1  - Tailspike proteins of three Podoviridae : genetic mosaics with conserved hreedimensional structure
N2  - Die Tailspike Proteine (TSP) der Bakteriophagen P22, Sf6 und HK620 dienen der Erkennung von Kohlenhydratstrukturen auf ihren gram-negativen Wirtsbakterien und zeigen, von den ersten 110 Aminosäuren des N-Terminus abgesehen, keine Sequenzübereinstimmung. Mit Röntgenkristallstrukturanalyse konnte gezeigt werden, dass HK620TSP und Sf6TSP ebenfalls zu einer parallelen, rechtsgängigen beta-Helix falten, wie dies schon für P22TSP bekannt war. Die Kohlenhydratbindestelle ist bei Sf6TSP im Vergleich zu P22TSP zwischen die Untereinheiten verschoben.
N2  - The bacteriophages P22, Sf6 and HK620 need their tailspike proteins (TSP) for recognition of surface carbohydrates on their gram-negative host bacteria. Sequence identity is completely lacking in their C-terminal 500 to 600 amino acids. The three TSP have the same fold, an oligomeric parallel beta-helix, as shown by crystal structure analyses of HK620TSP and Sf6TSP. Compared with P22TSP, the carbohydrate binding site of Sf6TSP is located at the interface between two monomers and not on a single monomer.
KW  - Bakteriophagen
KW  - Skleroproteine
KW  - Helix <beta->
KW  - Lipopolysaccharide
KW  - parallele beta-Helix
KW  - genetisches Mosaik
KW  - Tailspike
KW  - Kohlenhydrat-Protein-Wechselwirkung
KW  - parallel beta-helix
KW  - genetic mosaicism
KW  - tailspike
KW  - carbohydrate binding site
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-6885
ER  -